Footage indicator for drilling



Aug. 24, 1943.

J. C. CONRAD ET AL FOOTAGE INDICATOR FOR DRILLING Filed Nov. 1941 Josha4 C, COD/PH?) VENTORS Q I Patented Aug. 24, 1943 FOOTAGE INDICATOR FORDRILLING Joshua C. Conrad and Harold L. Conrad,

Oklahoma City, Okla.

Application November .8, 1941, Serial No. 418,554

6 Claims.

This invention relates to well drilling equiplogging the footage ofwells during drilling.

The principal object of the invention is to provide, in combination withan electrically operated counter, means responsive to movements of thebit in the well for actuating said counter, but with provisions forrendering the said means inoperative during periods when the bit iselevated from the point of operations, in order to insure accuracy inindicating the depth penetrated by the bit.

Another object of the invention is to provide a footage loggingapparatus whose calculations are electrically accomplished bytranslating mechanical movements into electrical impulses; that is tosay, by causing a magnetic counter to operate at intervals determined bythe movement of a line whose movement is in direct ratio to the movementof the bit in the well but, in the present case, is restricted to thedownward movement of the bit through provisions for breaking theelectrical circuit to the magnet during upward movements of the bit.

With the foregoing objects as paramount, the invention has particularreference to certain features of accomplishment to become manifest asthe description proceeds, taken in connection with the acompanyingdrawing wherein:

Figure 1 is a partial view of a rotary well drilling rig with theinvention installed thereon.

Figure 2 is a side elevational view of the invention with parts brokenaway andparts in section.

Figure 3 is a view on line 33 on Figure 2.

Figure, 4 is a plan view in transverse section, taken on line 4-4 onFigure 3, and

Figure 5 is a detail elevational view of the circuit making and breakingdisc.

In Figure 1 is shown the derrick 46, rotary table 41, kelly 48, swivell9, drilling line 50, traveling block 5| and crown block 52. A line 53is connected at d to the swivel or kelly and extends over a sheave inthe crown block and is threaded through a sheave 54 which is a part ofthe traveling block 55 and is passed upward and anchored at e to thecrown block 52. y

In the present case a sheave 54 determines the intervals between theelectrical impulses which actuate the counter 56, the said sheave havinga circumference whose measurement is predetermined to represent, forexample, one foot of hole drilled. In other words, upon each completerevolution of the sheave 54, a circuit is completed to the magneticcounter 56 to actuate the same to indicate a depth of one footpenetrated by the drill bit. This is accomplished in the manner tobecome apparent presently,

A housing 51 is mounted on the block and may contain a quantity of oil.One end of the stub shaft 58, on which the sheave 54 is mounted, extendsinto the housing 51 and carries thereon a disc 59. This disc is made ofnon-ferrous material, such as fiber and has an electrode extendingoutwardly from its periphery, Attached to the inner face of the disc isa ferrous plate 5 I, having an integral segment 62 extending outwardlytherei'rom and overlying the periphery of the disc be adjacent to theelectrode 60.

Connected to and insulated from the wall of the block 55 is a springcontact 53 which extends into the circular path of the electrode andengages the same at each revolution of the disc 59. A companion springcontact 64 is mounted on but insulated from the block 55 andfrictionally bears against the surface of the ferrous plate 6| of thedisc and has the function of a brush contact. 7

Referring to Figure 2, it will be observed that a wire is connected tothe contact 63 and extends to one post of the battery 66, (Fig. 1) thelatter being connected to the magnetic counter 56 by a wire Bl. Anotherwire 68 connects the counter with the contact 54 in the housing5'l.

In operation; as the bit drills into the formation, the kelly islowered, gradually lowering the line 53 which causes the block 55 totravel upward at half the ratio of the downward travel of the kelly. Aweight 65, constrained to rectilinear travel by a guide rail 'luprevents undue swinging motion of the block 55.

As the sheave 54 of the block 55 rotates, the disc 59 is rotated,bringing the electrode 60 into engagement with the spring contact 63. Asthe disc continues to rotate, the electrode advances and the contact 63,due to its inherent resiliency, snaps ofi the electrode, striking thesegment 62 of the ferrous plate 6|. The plate is momentarily charged andthe current from the battery 66, through contact 64 and wire 58.

to the magnetic counter 56 and back to the battery through wire 61 orground.

Thus, it will beseen that each time the bit penetrates to a depth of afoot, the sheave 54 will have made one complete revolution and the disc59. being amxed to the axis of the sheave, has also made one completerevolution, closing the circuit and thereby actuating the magneticcounter, by which is determined the depth of the hole.

It will be understood that more than one electrode, such as 60, may beemployed and other factors changed in keeping with such alterationwithout departing from the spirit and intent of the invention as setforth in the following claims.

What is claimed is:

1. Apparatus for indicating the depth penetrated by a drill bit indrilling wells, a line normally under tension, one end of whichisconstrained to move in direct relation to the downward movement of saiddrill bit, and having its opposite end anchored against movement, asheave block containing a sheave carried upon and actuated by said lineand whose displacement is equal to one-half the travel of said drillbit, a magnetic counter, a source of electrical current, an electriccircuit connecting said source and counter, a housing mounted on oneside of said sheave block, a disc mounted in the shaft of said sheaveand operating in said housing, an electrode extending from the peripheryof said disc, a ferrous plate on the face of said disc, a slidingcontact in continuous engagement with said plate, a resilient contactintermittently engaged by said electrode to open and close said circuitwhereby to progressively operate said magnetic counter, a weightsuspended from said sheave block and means for guiding said weight tocause said sheave block to travel in a substantially vertical plane.

2. Apparatus for indicating the footage made by a drill bit duringdrilling, a line having one end anchored and its opposite end connectedto the drill pipe carrying said bit to move therewith, a sheave andsheave block supported by said line intermediate its ends whereby itsdisplacement will be equal to one-half the displacement of said drillhit, an electrical circuit, a magnetic counter in said circuit, a sourceof electrical current, a disc carried by the axle of said sheave andactuated by movements of said sheave block, a ferrous plate mounted onthe face of said disc, a resilient contact in continuous engagementtherewith, an electrode extending from the periphery of said disc, asecond contact engaged by said electrode-at each revolution of said discto open and close said circuit at predetermined intervals to operatesaid counter, and weight means to constrain said sheave block againstother than vertical displacement.

3. An apparatus of the character described, in combination with thedrill bit and string of drill pipe in a well, a line connected at oneend to said drill pipe and having its opposite end anchored againstmovement, a sheave and sheave block carried by said line whose verticaldisplacement is half that of said drill bit, an electrical circuit,means for energizing said circuit, a magnetic counter in said circuit,means mounted upon and rotated by the axle of said sheave carrying aferrous plate, a contact in continuous engagement with said plate, anelectrode at one point on the periphery of said rotated means, a secondcontact engageable at each revolution of said rotated means to make andbreak said circuit-whereby to produce impulses for actuating saidcounter, a weight suspended from said sheave block and guide means forsaid weight to hold said sheave against other than verticaldisplacement.

4. Apparatus for indicating the footage made by a drill bit during thedrilling of a well, a line having one end connected to the string ofdrill pipe carrying said bit and having its opposite end anchoredagainst movement, a sheave block mounted on said line intermediate itsends and movable thereby, an electrical circuit, means energizing saidcircuit, means arranged in said circuit and operated by impulsesproduced in said circuit to indicate depth in feet penetrated by saiddrill bit, a disc carried by the shaft of the sheave of said block androtatable therewith, an electrode carried by the periphery of said disc,a ferrous plate carried by said disc having a peripheral extensionoverlying the periphery of said disc, a sliding contact in continuousengagement with said plate and a companion contact arranged forsuccessive engagement with said electrode and the extension of saidplate to momentarily charge said plate to make and break said circuittherethrough, whereby to operate said indicating means.

5. Apparatus as set forth in claim 4 in which the circuit is providedwith means to open the same during periods when the drill bit is beingelevated.

6. Apparatus as set forth in claim 4 in which the sheave block is heldagainst other than vertical displacement by a weight suspended therefromand means to constrain said weight to travel rectilinearly.

JOSHUA C. CONRAD. HAROLD L. CONRAD.

